Abi and Betty have $281. Jen and Abi have $338. The ratio of Betty to Jen is 4 : 7. How much does Abi have?
Amount that Betty has = 4 u
Amount that Jen has = 7 u
The amount that Abi has is the repeated identity.
Abi + 4 u = 281 --- (1)
Abi + 7 u = 338 --- (2)
(2) - (1)
7 u - 4 u = 338 - 281
3 u = 57
1 u = 57 ÷ 3 = 19
From (1):
Abi + 4 u = 281
Abi + 4 x 19 = 281
Abi + 76 = 281
Amount that Abi has
= 281 - 76
= $205
Answer(s): $205
